GCMRC 2019 Annual Reporting Meeting Preview Part 1 Adaptive - - PowerPoint PPT Presentation

U.S. Department of the Interior U.S. Geological Survey

GCMRC 2019 Annual Reporting Meeting Preview – Part 1

Adaptive Management Work Group Meeting March 6-7, 2019 Scott VanderKooi and Mike Moran U.S. Geological Survey Southwest Biological Science Center Grand Canyon Monitoring and Research Center

Overview

• A bit on the fishy side
• More diversity in Mike’s talk tomorrow
• Emphasis on recent results and long-term

trends

• HFE assessment – next week
• Bug flows update

(March 6, 2019)

Humpback Chub

(March 6, 2019)

(March 6, 2019)

Spring Abundance of Adult Humpback Chub: Little Colorado River

(Preliminary Data from VanHaverbeke et al. USFWS. 2018. Do Not Cite.)

2018 spring abundance estimate for sub-adults and adults similar to 2017. Adult abundance upward trend since 2015 continued.

(March 6, 2019)

Adult Humpback Chub Abundance (Adults ≥ 200mm TL in Little Colorado River aggregation)

(USGS Preliminary Data, 2019. Do Not Cite.)

Adult abundance as estimated in multi-state model is stable (or increasing slightly) and exceeds 2016 BiOp tier-1 trigger level of 9,000.

Year

Vertical lines represent 95% confidence intervals.

(March 6, 2019)

Spring Abundance of Sub-Adult Humpback Chub: Little Colorado River

2018 spring abundance estimate for sub-adult humpback chub (150-199 mm) in the Little Colorado River. 3-year average is 1,895 fish, exceeds 2016 BiOp tier-1 trigger level of 1,250.

(Preliminary Data from VanHaverbeke et al. USFWS. 2018. Do Not Cite.)

(March 6, 2019)

Fall Abundance of Sub-Adult Humpback Chub: Colorado River – JCM Reach

(USGS Preliminary Data, 2019. Do Not Cite.)

(March 6, 2019)

Year

Vertical lines represent 95% confidence intervals.

Fall abundance estimates for sub-adult humpback chub (150-199 mm) in the mainstem Colorado R. near Little Colorado R. confluence. 3-year average exceeds 2016 BiOp tier-1 trigger level of 810.

July Abundance of Age-0 Humpback Chub: Little Colorado River

(USGS Preliminary Data, 2019. Do Not Cite.)

Although adult abundance is steady (or possibly increasing slightly), little age-0 production seen in the LCR for the past 3

• years. If this continues, may see a decrease

in adult abundance in the next 3-5 years.

(March 6, 2019)

Year Vertical lines represent 95% confidence intervals.

Apparent Survival Humpback Chub: Translocated vs Not Translocated

Assume if 300 fish are translocated yearly in perpetuity, adult abundance would be 350 adults higher vs. if no translocations occurred.

(USGS and USFWS Preliminary Data, 2019. Do Not Cite.)

(March 6, 2019)

Apparent Survival

 Nonnative trout removals  Humpback chub translocations  Multiple monitoring metrics: abundance, survival,

recruitment

(Slide courtesy Brian Healy, NPS)

(March 6, 2019)

NPS Tributary Native Fish Restoration: Bright Angel Creek and Havasu Creek

Bright Angel Creek: Trends

• Strong BNT year class in 2018:

likely due to ideal (low) flows during spawning/incubation

• Very few adult BNT remaining
• 2018 BNT abundance = 84%

decline since 2012 (>90% in 2017)

• Weak year classes of native fishes

(likely due to drought)

2018 (red) adults

2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 2012 2013 2014 2015 2016 2017 2018

Abundacne Estimate - 2-pass data

Bright Angel Creek: total, young-of-year, adult abundance

total >230 YOY

(Slide courtesy Brian Healy, NPS. Preliminary data, do not cite)

(March 6, 2019)

Bright Angel Creek: Trends, cont.

• Strong BNT year class in 2018:

likely due to ideal (low) flows during spawning/incubation

• Very few adult BNT remaining
• 2018 BNT abundance = 84%

decline since 2012 (>90% in 2017)

• Weak year classes of native fishes

(likely due to drought)

2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 2012 2013 2014 2015 2016 2017 2018

Abundacne Estimate - 2-pass data

Bright Angel Creek: total, young-of-year, adult abundance

total >230 YOY

Young trout flood vulnerability

(Slide courtesy Brian Healy, NPS. Preliminary data, do not cite)

(March 6, 2019)

Humpback c k chub translo locatio ions

Havasu Creek:

• Population estimate ~300
• Non-translocated/fish

produced in situ catch continues to increase (~50% of abundance estimate in May, 2018) Bright Angel Creek:

• May, 2018, Released 116

adult humpback chub (mean TL =257 mm)

• Preliminary apparent

survival ~80%; estimate will change with additional data

• Comparable to some

0.7 0.75 0.8 0.85 0.9 0.95 1

Monthly survival Cohort or Shinumo Creek time period (time-varying model)

Apparent survival - all translocations

* *BAC - Preliminary estimate

(Slide courtesy Brian Healy, NPS. Preliminary data, do not cite)

(March 6, 2019)

Background image only - 2

(March 6, 2019)

Humpback C Chub C CPU PUE E by y year i in western Grand C Canyon

Year

Mean Captures per Hoop Net Set (n)

(Preliminary Data from VanHaverbeke et al. USFWS. 2018. Do Not Cite.)

(March 6, 2019)

Upstream Downstream Humpback chub CPUE in western canyon peaked in 2017. Despite a year

• ver year decline, 2018

catches remained well above levels observed prior to recent increases. All size classes (juvenile to adult) were captured.

Rainbow Trout and Brown Trout

(March 6, 2019)

Background image only - 3

(March 6, 2019)

Rainbow Trout (≥ 175 mm FL) - Glen Canyon

(Preliminary data from Yard and Korman, 2018. Do Not Cite.)

Rainbow trout catch increases seen in all size classes in 2018 likely due to high production and survival in recent years.

(March 6, 2019)

Rainbow Trout (all sizes) - Glen Canyon Catch Per Unit Effort (CPUE)

200 400 600 800 1,000 1,200 1,400 1,600 Jan-2014 Apr-2014 Jul-2014 Sep-2014 Oct-2014 Dec-2014 Apr-2015 Jul-2015 Sep-2015 Oct2015 Dec-2015 Jan-2016 Apr-2016 Jul-2016 Sep-2016 Oct-2016 Jan-2017 Apr-2017 Jul-2017 Sep-2017 Oct-2017 Jan-2018 Apr-2018 Jun-2018 Sep-2018 Nov-2018 Feb-2019

RBT CPUE (# fish / km) SAMPLING PERIODS

CPUE based on 1st Pass

(Preliminary data from Yard and Korman, 2018. Do Not Cite.)

(March 6, 2019)

Rainbow trout catch peaks in the fall as young fish become susceptible to gear. Catch drops over winter due to lower survival rates of young fish. Observed year over year increases from 2015 – 2018 with a big jump in 2018. First look in 2019 – similar to 2018.

Lees Ferry Rainbow Trout length frequency histograms

High levels of juvenile production 2016-18. Recruitment into larger size classes becoming more evident, especially in 2018. 1 gridline = 50 fish 5 mm bins

* *No Spring trip in 2018

(Preliminary Data from Rogowski et al. AGFD. 2019. Do Not Cite.)

(March 6, 2019)

Lees Ferry Rainbow Trout angler CPUE

Goal: CPUE ≥ 1 fish/hr

Goal: Angler catch rate ≥ 1 Rainbow per hour

(Preliminary Data from Rogowski et al. AGFD. 2019. Do Not Cite.)

(March 6, 2019)

Angler catch rates are increasing in both the upriver boat fishery and the walk-in fishery. Boat fishery just below goal in AG&F management plan for Lees Ferry.

Rainbow Trout - Glen Canyon Relative Condition Factor (300 mm fish)

(Preliminary data from Yard and Korman, 2018. Do Not Cite.)

(March 6, 2019)

Results from October Surveys in Three Sample Reaches Condition lowest in 2014, coincided with sharp decline in

• abundance. Values >1

since late 2015 provides indicator that fish in Glen Canyon are healthy.

Brown Trout CPUE

2 orders of magnitude less than rainbow trout

• 51 captured

– Released 9 in TRGD reaches (5 tagged, 4 recaptures) – Removed 42 elsewhere (including 2 recaptures)

(Preliminary Data from Rogowski et al. AGFD. 2019. Do Not Cite.)

(March 6, 2019)

Brown trout catch by AG&F flat from 2016 through 2018 and still comprise

• nly a small proportion of

fish in Glen Canyon.

Stocked Triploid Rainbow Trout - Glen Canyon

AGFD released 526 triploid rainbow on Nov. 14, 2018 just upstream of Lees Ferry (RM 0). GCMRC recaptured 3 in Glen Canyon near - 4 mile on Feb. 10-11, 2019. No indication of substantive growth. No stocked fish were captured in upstream sample reaches. Recapture Locations Release Location

(USGS Preliminary Data, 2019. Do Not Cite.)

(March 6, 2019)

(March 6, 2019)

Bug Flows

What is a Bug flow?

• “Give bugs the weekends off”
• Weekend stable low flows from May-August
• Eggs laid on weekends never dry

https://waterdata.usgs.gov/az/nwis/uv?site_no=09380000

Midge spatial catch pattern (prediction)

• Midge spatial

pattern due to hydropower releases

• Bug Flows should

minimize effect

• Troughs,

particularly, should flatten

(March 6, 2019)

(USGS Preliminary Data, 2019. Do Not Cite.)

Midge spatial catch pattern (result)

• Spatial pattern

evened out in 2018

• Effect should be

stronger if bug flows approved for 2019 (after a year of bug growth)

• 3 years of bug flows

recommended by GCMRC to test hypothesis

(March 6, 2019)

(USGS Preliminary Data, 2019. Do Not Cite.)

Yearly light trap patterns

• Midges stable
• Caddisflies take
• ff in 2018
• Caddisflies now

approximate midge densities

(March 6, 2019)

(USGS Preliminary Data, 2019. Do Not Cite.)

Bug Flows weekdays vs. weekends

• Midge adults more

abundant on weekends

• Behavioral

response to steady, low flows?

• Some evidence

angling improved during bug flows. Response of fish and/or anglers?

(March 6, 2019)

(USGS Preliminary Data, 2019. Do Not Cite.)

Acknowledgements

• U.S. Department of the Interior, Bureau of

Reclamation and the Glen Canyon Dam Adaptive Management Program

• Arizona Game and Fish Department
• National Park Service
• US Fish and Wildlife Service
• Ecometric Research, Inc.
• U.S. Geological Survey, Southwest Biological

Science Center, Grand Canyon Monitoring and Research Center

(March 6, 2019)

Questions?

(March 6, 2019)